Rectifier arrangement for switching purposes



Patented Apr. 4, 1950 RECTIFIER ARRANGEMENT FOR SWITCH- ING PURPOSESOtto Tschumi, Soleure, Switzerland, assignor to AutophonAktiengesellschaft, Soleure, Switzerland, a joint-stock company ofSwitzerland Application May 12, 1944, Serial No. 535,295 In SwitzerlandDecember 4, 1942 Section 1, Public Law 690, August 8, 1946 Patentexpires December 4, 1962 1 Claim. 1

This invention relates to rectifier arrangements for switching purposes.Rectifier arrangements for switching purposes which can be connectedwith current consuming elements quite independent of the kind anddirection of current (socalled single-phase Gratz-full path-rectifierarrangements) are well-known. In different con-- nections it has beenfound desirable to provide similar simple arrangements which are notonly independent of the kind and direction of current, but have valvequalities.

The rectifier arrangement according to the invention is characterised inthat, besides the means serving exclusively for rectifying, it cmprisescurrent consuming elements independent of the kind and direction ofcurrent and others which are dependent on the kind and direction ofcurrent.

The accompanying drawings illustrate, by way of example, in

Fig. l the diagram of an embodiment of the device according to theinvention and in Fig. 2 the diagram of an example of the use of thisdevice.

In Fig. 1 the terminals are designated by the reference characters I and2. Between these terminals is connected a Gratz full path-rectifierarrangement with rectifier elements a, b, c, d arranged in a square,opposite corners of the square being connected with the terminals I and2. A current consuming element which is independent of the kind anddirection of current is connected across the corners of the square otherthan those with which the terminals I and 2 are connected. The currentconsuming element II is connected in series with the rectifier element aand parallel to the rectifier element 0, while the current consumingelement L is in series with the rectifier element b and parallel to therectifier element d. The two current consuming elements may, e. g., beconstituted by a relay winding (II) and a visual signal in the form ofan electric lamp (L).

The manner of operation of the arrangement according to the invention isthat, in the case of a direct current with the positive pole l and thenegative pole 2, a path of direct current is formed over +l-aI-cZ-2 anda parallel path over +laII2-- Upon reversal of the poles, the twofollowing parallel and +2Lb-l- The resistance of one of the currentconsuming elements being always greater than that of the rectifierelement connected in parallel thereto, the following circuits occur forthe two service conditions with regard to the elements II and L: Ifterminal I is positive: +-la-II2; if terminal 2 is positive: +2L-b-l-.From this it may be seen that, independent of the change of polarity ofthe terminals I and 2 the current always passes in the same directionthrough the current consuming element I, while the current consumingelement II only carries current when the pole is positive and thecurrent consuming element L carries current when the pole l is negative.In this simple rectifier arrangement one succeeds in connecting bothelements independent of the kind and direction of current and alsoelements dependent on the kind and direction of current, so that thisarrangement has the features of a continuous contact as well as of avalve.

If an alternating current is used, the current consuming element Ireceives the whole current, while the two others absorb only half aperiod, which fact in the example shown, would result only in a flashingof the lamp L at half luminous intensity.

The example of the use illustrated in Fig. 2 of the device according tothe invention is in a subscribers device for selectively loud or faintlyaudible traffic, the change of the speaking direction in the case ofloud trafiie being manually effected.

EW is a transducer which can be switched so as to Work as a receiver oras a transmitter. This transducer is connected with the transformer UEthrough an amplifier V having an input transformer E and outputtransformer A and a circuit closer 61 for connecting the amplifier witha source of alternating current. The amplifier V can be connected to thetransducer EW in both directions by the relay contacts ur and in. Thecenter point of the winding of the transformer UE on the line side isconnected with one free end (terminal a) of the winding through thetelephone receiver T and the contact TK1 while bridging-over one half ofthe winding. Between the winding ends connected to the transmissionconductors a, b and impedance coil Dr is placed, the center point ofWhich is grounded through the contact ES, the contact 62, the deviceaccording to the invention, and the impluse contact i 01' the callingdial NS. The contacts ES and e: are bridged-over by the condenser CI,while over the condenser CII and the visual signal TZ, the middle of theimpedance coil Dr is directly connected with the impulse contact 2'.

The arrangement has here, too, a Gratz-fulL- path-rectifier arrangementcomprising four rectifier elements connected to one another in a knownmanner. As a current consuming element which is independent of the kindand direction of current, a relay E is provided, the center point ofwhich is connected with the off-normal contact is of the calling dialNS. The elements dependent on the kind and direction of current are therelay U, the visual signal SZ and the resistance We; U and SZ, on theone side, and We, on the other side, being connected in parallel todifierently directed rectifier elements. The relay U can be disconnectedby the switch hook TK2 and the resistance W3 by the switch hook TKs. Thecontacts e1 and e2 are contacts of the relay E and are closed when therelay is energized. The contacts ur and uz are contacts of the relay U.The switches TKI, TKz and TKs are hook switches of the telephonereceiver T. I

The manner of operation of the arrangement shown is as follows:

On a call of the illustrated subscribers device two current sources notshown connected in series are in relation with the terminals 0, and b.These two sources consist of an alternating current source and a directcurrent source whose negative pole is connected to the terminals. Owingto the open position of contact e2 and to the illustrated connection ofthe condensers CI and 011 a direct current path is not formed initially,but an alternating current circuit is established from the groundedalternating current source over the impedance coil Dr and from here, onthe one side, over CI and the device according to the invention and, onthe other side, over the condenser CII, the visual signal TZ and then,together, over the impulse contact 2' to ground. The alternating currenthas the effect that the relay E, being independent of the kind anddirection of current, is energized. Likewise, the relay U and the visualsignals S2 and 'IZ respond, while a polarised direct current flowsthrough the resistance W3. By the action of relay E, the contacts 61 and22 are closed, so that the amplifier V is switched-in and a directcurrent path is provided over impedance coil Drcontacts EScontact e2thedevice according to the invention-impulse contact 2' and from here toground. If the alternating current source is now disconnected, the relayE being an element independent of the kind and direction of currentrelay U and the visual signal SZ remain in their I former operatingconditions; resistance W3 carries no current and the visual signalforming an electric lamp TZ is extinguished. The action of the relay Ucauses the operation of the relay contacts w and d2, whereby thesubscribers station is changed-over from the represented operatingcondition for speaking to that for listening. With the aid of a means,which is not the object of the present invention, the poles of thedirect current source are interchanged, i. e., in place of the positivepole which has been grounded till now, the negative pole is connectedwith ground and the positive one with the terminals a, b. Owing to thispole-changing, relay E remains in its operating condition, while relay Udrops and the electric signal lamp SZ is extinguished. Thereby, theposition of the switches U1 and us is again changed, the speakingdirection altered and the illustrated subscribers station again broughtinto the operating condition for speaking. It is thus possible in thearrangement shown to alter by a simple pole-changing the speakingdirection and to control a visual signal, while, in spite of this, therectifiers remain constantly switched-in.

If the subscriber now uses the telephone receiver T, the switch hooksTKi, TK2, TKz are operated. Closing switch hook TK2 results in areduction of current, while on opening the other two switch hooks TK2and TK3 the relay U and the resistance W3 are finally disconnected. Bythis reduction of current means are operated in the main station,allowing a weaker alternating current to be superimposed on the directcurrent. The visual signal TZ comes into action and informs the otherstation that the subscriber uses the receiver. Since relay U isdefinitely disconnected, the speaking direction can no longer bechanged, and the transducer EW remains constantly connected astransmitter. A change in the direction of current is, therefore, quiteimmaterial for the subscriber using the receiver but has only aninfluence upon the device of that subscriber who desires to have a loudconversation. When the latter is finished the calling station operatesthe contact ES. Thereby the direct current is interrupted, relay E dropsand opens the contacts 61, 62, contact e1 thereby disconnecting therectifier, and contact as finally interrupting the direct current path.

Therefore, with the arrangement according to the invention, theswitching-over of the speaking direction is locked for the subscriberdesiring a faintly audible traffic, while for the subscriber wishing touse the loud speaker, it remains quite intact. Besides this, the samedevice lets the subscriber know by a visual signal that the faintlyaudible traific is in use.

What I claim is:

In an electro-acoustic circuit, a switching and signal device comprisinga full wave rectifier comprising four rectifier elements connected in asquare with opposite rectifier elements reversed in direction, means forconnecting one pair of opposite corners of said square with a linecarrying signal current, a relay connected across the other pair-ofopposite corners of the square and responsive to line current in bothdirections, a second relay connected in parallel with one of saidrectifier elements and fully responsive to line current in one directionand a signal device connected in parallel with an adjacent rectifierelement and fully responsive to line current in the opposite direction.

OTTO TSCHUMI.

No references cited.

